No dinner party would be complete without some apéritifs to wet the appetite. Before mixing up some gin and tonics, Chris Smith caught up with Will Lowe, Master Distiller of the Cambridge Distillery, who explained a little bit about the science of distilling gin, and how ants are providing him with funky new flavours...
Will - So the Cambridge distillery is a unique distillery. We focus mainly on the production of gins but the way we make gin is different to pretty much everybody else in the world makes gin.
Chris - Can you just explain actually what is gin because I know I like it, I know how to drink it but I've no idea really what it is and what goes into it? I know it's got something to do with juniper.
Will - Sure and that's the start point really. Gin is just a spirit which is predominantly juniper flavoured but the way that that flavour gets there is very important. So the way most people gin is you start effectively with a very large pot, fill that with a neutral alcohol, and then add your juniper to that along with other botanical ingredients. Then you boil all that up, collect the vapour that results, condense that back into a liquid - that's gin. But that's not how we do it...
At the Cambridge distillery we take the observation that not all ingredients like to be boiled at the same temperature. In fact, some don't like to be boiled at all so we separate all the ingredients out and apply vacuum distillation. This allows us to reduce boiling temperatures so, in the case of things that are more delicate, cucumber rose for example, instead of increasing the temperature we simply drop the pressure right down so we can just lift the flavour off.
Chris - So instead of actually boiling up this giant stew and keeping the vapour and chucking the stew residue away, you're actually saying we can boil things off at a much lower temperature and, therefore, we may not get this deleterious, destructive effect on some of these more delicate ingredients? You can get them into the final product rather than just boiling them away?
Will - Yes, that's exactly the principle. So instead of having one big pot, we've got lots and lots of little individual chambers. We control the boiling point because of the pressure (different temperature in each case), so much lower temperatures for the much more delicate flavours.
Chris - Tell us about how you actually blend a gin or what is the anatomy of a good gin if you like?
Will - I like to think of a gin as having base notes, heart notes and top notes. This is something that really brushes shoulders with the perfume industry in many ways.
So with base notes for example, the key base note here will always be juniper. I've got some here for you to try actually. This is a juniper distillate so if you taste that you'll notice it's base notes typically tends to be characterised by being relatively bold flavours but relatively simple flavours.
Chris - I'll give this a try. So this is just a clear colourless liquid... It just actually tastes like cheap gin if I'm honest. It's just literally got that flavour of gin but just tastes like vodka and some junipery flavour.
Will - Yes. That is gin without its clothes on. That's a naked gin for a naked scientist. Where the character comes in, that's where we add a heart note. So at this point it's useful to understand a bit about how flavour actually works. Flavour being a combination of your sense of taste, which is what happens in your mouth. The way you have sweet, sour, bitter, acidity and umami and then you've got smell so olfaction. There are two routes to that, one through your nose so smelling as most people would call it but also orthonasal olfaction as we call it, and then backwards through the back of your throat, which is retronasal olfaction, and these interact very differently. A way of demonstrating this - I've got a spirit here that I'll put into a pipette and ask you if you can to put it into your mouth but with your nose held. Do you want me to hold your microphone?
Chris - You hold my microphone so I'm going to hold this pipette, I'm going to hold my nose and squirt this in my mouth...
Will - There you are. Now try and swallow with your nose still held.
Chris - Okay done that.
Will - You taste almost nothing and then when you release your nose... breath in and out.
Chris - Ohh. Oh it's a beautiful lemony flavour. Do you know I used to do the same thing with brussel sprouts when I was at school because I hated them, and I found if I held my nose I didn't have to taste them. That's the same principle?
Will - Exactly the same. By cutting off that access to retronasal olfaction, you can really dampen the flavour right down or the opposite as we just saw in there.
Chris - How does this apply to gin though?
Will - We use a heart note as something that you can identify by ortho and retronasally, so it's that character that you'll pick up when you nose the gin but it's also a really persistent flavour after you've swallowed it.
Chris - Yes, I can still taste that lemony essence now.
Will - So the opposite of that, in many ways, is the top note which I've illustrated here by using an atomizer. It's like a perfume bottle a bit of perfume you can spray directly into your mouth.
Chris - So this is a big square bottle; it's got a squirty thing on the top like perfume. I'm going to spray this just on my tongue, yes?
Will - Straight into your mouth.
Chris - Oh, OK. That's a rosy flavour. It's like rose but it wasn't like the lemon one which I could still taste minutes ago. That was there in a flash. It was like someone detonated a sudden explosion in my mouth that was over in a flash, it's gone.
Will - And that's exactly what we use a top note for. By using the atomiser we're massively increasing the surface area there. It gives you a really intense strong hit but then it disappears. It's almost ethereal, a really sort of elusive element of the flavour that we balance. So what we do is we take all these elements together, wrap those up into one single flavour as it were and then that's how we make gin. But, of course, because not all people are the same, we also offer a gin tailoring service where we can do this and fit a particular gin to each individual person's particular palette.
Chris - Now you've educated me about how you do all this, does this mean Will that you could make gins from ingredients that would, I suppose, be regarded as unusual?
Will - It means exactly that. Certainly the weirdest one I think could be anti-gin.
Chris - Anti-gin, like antifreeze?
Will - Anty gin like ants as in creepy crawlies made from actual ants, yes.
Chris - How do you do that?
Will - Long story short, this was a collaborative project between us and the Nordic Food Lab. They made the observation that some ants from some places have very specific flavours. We actually used a red wood ant which is cytrusy. If it were just a citrus flavour we would use lemons, they don't run away, they don't try and bite you, but they have a completely unique flavour. And all gins have a citrus flavour in them somewhere as well so.
Chris - How do you get the flavour out of an ant? Do you go and dig up and ants nest and just get millions of ants and just do what you would do if they were juniper berries?
Will - Well actually what we do is we work with a chap called Miles Irving, who is a forager in South Kent, and he very cleverly waits for these ants to be on the move. So they go very deep underground to avoid the frost during winter and then in the spring they start to swarm. Now it's very important to us that we use happy ants because if you get upset ants then they express their discomfort by spraying formic acid. Now that's the bit that we actually want so we use these happy ants. Miles will put down a sheet that they crawl over on their swarming journey and pick that up and sort of gently shake them into a high strength ethanol, which conserves the formic acid and despatches them in as humane a way as possible. That ethanol comes back up to us in Cambridge where we distill it.
Chris - Can I have a go?
Will - Of course. So what I'd like to show you first of all is the ant distiller. So this is what the ants taste like when distilled, so this is pure ant distillate.
Chris - Here we go...Mmm it's not at all unpleasant and it's quite a subtle flavour. It tastes gin-y without any actual gin there.
Will - This is how we knew immediately on first tasting that this was a project that was going to be successful.
Chris - Right, so what, you blend that in with your other notes now to get that very nice rustic flavoured gin?
Will - That's right and this is the result.
Chris - It looks like a clear colourless liquid. OK here we go, let me try... Well it's extremely pleasant and it's much more complex and much more interesting than the rather boring base that we tried earlier. Which is a good thing because if it wasn't, obviously there'd be a problem. But no, that's delicious